Mars is not the arid planet that we thought of in the past. Images released by NASA show streaks down craters, which infer the flow of water:

The historic announcement is fueling Mars mania. The red planet has been the subject of endless fascination. Everything from Mission To Mars, Total Recall, War of the Worlds, and The Spoof Mars Attacks.

NASA's announcement comes as a new movie about surviving on Mars - The Martian, starring Matt Damon - is about to be released.